Auxilliary brake for automobiles



P. A. ROBBINS.

AUXILIARY BRAKE FOR AUTOMOBILES. APPLICATION FILED AUG-13,1911.

1,431,182. ,Patented Oct. 10,1922.

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Patented Get. 10, 1922.

are sass PERCY A. ROBBINS, OF SAN FRANCISCO, CALIFORNIA.

AUXILIARY BRAKE FOR AUTOMQBILES.

Application filed August 13, 1921. 'Serial No. 492,139.

To all whom it may concern:

Be it known that I, PERCY A. ROBBINS, of the city of San Francisco, in the county of San Francisco, in the State of California, a

citizen of the United States of America,

have invented certain new and useful Improvements in Auxiliary Brakes for Automobiles, of which the following is a speci fication.

This invention relates to brakes parti'cu-' larly adapted for use in automobiles when travelling down long inclines. Friction brakes when much used become very hot, which necessitates the automobile being stopped until the brakes cool off. When travelling on long inclines it is an unpleas ant and fatiguing task for the operator'to continuously apply the ordinary friction brakes, and my object is to arrange the water circulating system, used for cooling the, engine cylinders, so that the pump therein may be used when the need arises to absorb more power than is normally the case,

brake.

I attain my object by means of the constructions hereinafter described and illustrated in the accompanying drawings in which Fig. 1 is a side elevation, partly in section, of my invention shown in position on an automoble;

Fig. 2 a rear elevation of the same; gig. 3 a detail in plan of the rock shaft; an

Fig. 4 a sectional detail of the pump discharge pipe.

In the drawings like numerals of reference indicate corresponding parts in the different figures.

1 is an automobile chassis on which the water cooled internal combustion engine 2 and the radiator 3 are suitably supported. The engine cylinders are provided with the usual water jackets through which water is circulated by means of a centrifugal pump 4 suitably carried by the chassis, The lower end of the radiator is connected to the pump 1 by means of the suction pipe 5. The pump discharge pipe 6 forms a communication withthe pump and the lower end of the The upper end of the water jacket is connected to theradiator by a return pipe 7.- The pump 4 is of ordinary construction, being provided with rotary blades or impellers 8 secured to a shaft 9 which is j ournalled in the glands of the stufling boxes 10. Theshaft 9 may be driven in any suitable manner though the preferred method isas follows. A pulley 11 secured to the shaft 9 is driven by means of a belt 13 from a pulley 12 'secured to the engine crank shaft. This water circulating arrangement for coolin engine cylinders is well known in the art.

1; is a well known fact in the art ofpumping liquids that the greater the quantity of liquid moved, in a given time against a constant pressure, the greater is the power consumption. A characteristic of centrifugal pumps is that any decrease in the head pumped against will result in an increase in the quantity of liquid moved, the increase in quantity being at a higher rate than can be accounted for by the decrease in head.

Another characteristic of centrifugal pumpsis that if a pump, which is designed to operate most efficiently at a given speed against a certain pressure, be operated against a lowered pressure, the speed being constant, then not only does the quantity of liquid pumped increase but the efficiency of the pump greatly'decreases and the power consumed in driving the pump is increased not only b the increased volume of liquid pilmpe but also by the lowered efliciency of the pump.

Normally when the engine is running the quantity of water circulated through the cooling system is sufficient to maintain the engine at a safe temperature and thehead pumped against is practically the friction head of thecircuit through which the water passes. The circuit has a relatively hlgh resistance to the flow of water owlng to the various bends and obstructionsto a free flow.

When an automobile travels down a grade of suflicient inclination its motion is caused by gravity and, of course, no power is required. Thereforet he entire cooling tem may be used for other purposes. It is evident that the speed of an automobile% travelling down an incline by means 0 gravity, may be controlled by any means that will absorb sufficient power. It is also evident that the friction head pumped against may be reduced, when des1red.-thus the flow of liquid is increased and at the same time the efficiency of the pump 1s reduced so that a considerable increase in the power required for pumping the water is sys-r developed. Of course, it is understood that the engine and thus the pump will be driven by means of the traction on the rear wheels of the automobile.

To enable the friction head tobe reduced when desired I provide the following means. The pump discharge pipe 6 is extended upwardly and forms a communication with the upper end of the radiator 3 and is provided with a connection 14 forming a communication with the lower end of the cylinder water jacket. The flow of water from the pump may be either directed to the water acket for cooling the engine cylinders or caused to pass directly to the upper end of the radiator by means of the valve 15 located in the discharge pipe 6 at a point intermediate the connection 14 and the radiator 3. The discharge pipe is preferably formed with an offset to provide diametrically opposite seats 16 for the valve 15.

It will readily be seen that should the valve 15 be opened that the pump 4; discharge pipe 6, radiator 3 and suction pipe 5 will form a complete circuit offering much less resistance to the flow of water than the complete. cooling cilcuit.

The suction pipe 5 is preferably of larger area than that required for the supply of water to cool the engine cylinders. A gate valve 17 slidably mounted in the suction pipe limits the supply of water to thepump when the latter is used for cooling purposes and is adapted to be adjusted to allow a greater flow of water through the suction pipe thus reducing the friction therein.

It is evident that with this arrangement the friction head may be materially reduced, when desired, thereby increasing the power consumption of the pum so that the latter'may be used as a brake t us preventing the automobile gaining velocity when travelling down an incline. Of course, the radiator will dissipate the heat of the water caused by the resistance to the increased flow.

The preferred arran ement for operating the valve 15 which is ournalled in the discharge pipe 6 and the gate valve 17 is as follows. To the spindle of the rotary valve 15 is secured a bell crank 18 and to one arm of the latter is pivotally connected a link 19. The other end of this link is pivotally connected to the gate valve 17, the preferred arrangement being to provide the upper end of the valve with an eye to receive the end of the link. A rock shaft 20 is journalled in the bearings 21, which are secured to the underside of the foot boards'of the automobile. To a rock arm 22 secured on the shaft 20 is pivotally connected one end of a 'connectingrod 23, the other end of which is pivotally connected to the second arm of the bell crank 18. A lever 24 secured on the shaft 20 extends through the foot boards arisa and is provided with a head 25 adapted to be engaged by the operators foot. It is evident that when the head 25 is depressed that the shaft 20 will be oscillated and the valves 15 and 17 opened. A spring 26 suitably connected to the bell crank and the radiator 3 normally tends to maintain the rotary valve 15 in its closed position and the gate valve 17 in a position to limit the flow of water through the suction pipe.

Should it be desired to use the braking effect of the pump in conjunction with the ordinary friction brake, I provide an arm 27 adapted to be engaged by the friction brake foot lever 28 to oscillate the shaft 20 when the lever 28 is depressed. Preferably the arm 27 is provided with an anti-friction roller to engage this lever.

What I claim as my invention is:

1. In a motor vehicle, the combination of a water circulating system including a radi ator, the water jackets of the motor of the vehicle, and a centrifugal pump; means whereby thepum-p is driven from the power plant of the vehicle to serve as a brake; and means for reducing when desired the head against which the pump works.

2. In a motor vehicle, the combination of a water circulating system including a radi-' ator, the water jackets of the motor of the vehicle, and a centrifugal pump; means whereby the pump is driven from the plant of the vehicle to serve as a brake; and means for short circuiting the cooling system to cut out the water jackets.

3. In a motor vehicle, the combination of a water circulating system including a radiator, the water jackets of the motor of the vehicle, and a centrifugal pump means whereby the pump is driven from the power plant of the vehicle to serve as a brake; means for controlling the flow to the pump; and means for short circuiting the cooling system to cut out the water jackets.

l. In a motor vehicle, the combination of awater circulating system including a radiator, the water jackets of the motor of the vehicle, and a centrifugal pump; means whereby the pump is driven from the power plant of the vehicle to serve as a brake; means for controlling the flow to thepump; means for short circuiting the cooling system to cut out the water jackets; and means for permitting freer flow to the pump simultaneously with said short circuiting.

5. In a motor vehicle, the combination of a water circulating system including a radiator, the water jackets of the motor of the vehicle; and a centrifugal pump; means whereby he pump is driven from the power plant of the vehicle to serve as a brake; a discharge pipe forming a connection with the ,pump and the upper end of the radiator; a connection forming a communication with the discharge pipe and the water jackets;

a point intermediate the radiator and the connection and adapted, when closed, to direct 'the flow of water from the pump through the connection to the water jackets and adapted, When opened, to allow the flow of water to pass directly to the upper end of the radiator.

6. A motor yehicle constructed as set forth in claim 5 in which the valve is journalled in the discharge pipe; spring means tend- -ing to maintain the valve in a closed position; and means adapted to open the valve.

7 In a motor vehicle, the combination of a water circulating system including a radiator, the water jackets of the motor of the vehicle, and a centrifugal pump; means whereby the pump is driven from the power plant of the vehicle to serve as a brake; a discharge pipe forming a connection with the pump and the upper end of the radiator; a connection forming a communication with the discharge pipe and the water jackets; a rotary valve journalled in the discharge pipe at a point intermediate the radiator and the connection; an arm secured tothe journal of the valve; a coil spring having one end connected with the arm and having the other end connected with a suitable stationary part and tending to maintain the valve in a closed position; a shaft journalled on the vehicle; a rock arm secured on the shaft; a connecting rod having one end pivotally connected with the arm and having the other end pivotally connected with the rock arm; a lever secured on the shaft whereby the latter may be oscillated to open the valve.

8. In a motor vehicle, the combination of a water circulating system including a radiator, the Water jackets of the motor of the vehicle, a centrifugal pump, and a suction pipe; means whereby the ,pump is driven from the power plant of the vehicle to serve as a brake; a discharge pipe forming a connection With the pump and the upper end of the radiator; a connection forming a communication with the discharge pipe and the water jackets; a valve located in the-discharge pipe at a point intermediate the radiator and the connection and adapted, when closed, to direct the flow of water from the pump through the connection to the Water jackets and adapted, when opened, to allow the flow of water to pass directly to the upper end of the radiator; and a gate valve slidably mounted in the suction pipe to limit the supply of water to the pump under normal conditions and adapted when opened to permit a freer flow of water through the pipe.

9. In a motor vehicle, the combination of a water circulating system including a radiator, the water jackets of the motor of the vehicle, a centrifugal pump, and a suctionpipe; means whereby the pump is driven from the power plant of the vehicle to serve as a brake; a discharge pipe forming a connection with the pump and the upper end of the radiator; a connection forming a communication with the discharge pipe and the Water jackets; a rotary valve journalled in the discharge pipe at a point intermediate the radiator and the connection; a' gate valve slidably mounted in the suction pipe to limit the supply of water to the pump under normal conditions and adapted when opened to permit a. freer flow of Water through the pipe; a bell crank secured to the journal of the rotary valve; a coil spring having one end connected with one arm of the bell crank and having the other end connected with a suitable stationary part and tending to maintain the rotary valve in a closed position; a shaft journalled on the vehicle; a rock arm securedon the shaft; a connecting rod having one end pivotally connected with the arm of the bell crank and having the other end pivotally connected with the rock arm; a link having one end pivotally connected with the second arm of the bell crank and having the other end pivotally connected with the gate valve; and a lever-secured on the shaft whereby the latter may be oscillated to simultaneously open the rotary valve and the gate valve.

10. In a motor vehicle provided with a friction brake, a foot lever adapted tooperate the brake, the combination of a water circulatin system including a radiator, the water jackets of the motor of the vehicle,

anda centrifugal'pump; means whereby the.

July, 1921. I

' PERCY A. ROBBINS. Witnesses: 1 p

MAE DAVIS,

Esrmnz EPSTEIN. 

